1. Field of the Invention
This invention relates to a side door hinge mechanism in a motor vehicle, in which a quadric crank chain mechanism is utilized.
2. Description of the Prior Art
In most cases, the side door in a motor vehicle, e.g. passenger car, is installed in a manner to be rotatable about a hinge affixed to a vehicle body for opening or closing. In order to allow an occupant of the motor vehicle to open or close the side door for getting in or out of the motor vehicle, a door opening angle corresponding to the total length of the side door is required. In certain circumstances, such as when a space at the side of the motor vehicle is small, there are many cases where it is difficult for the occupant to get in or out of the vehicle because the side door cannot be opened sufficiently.
To overcome these difficulties now, it has been desirable to use a front rotary link, which is formed by interconnecting the front portion of the side door, possibly the foremost point, and a position forward of the front pillar of the vehicle, so that the side door is slidable forwardly to a considerable extent.
However, if the above-described arrangement is adopted, then the front rotary link and the front fender generally interfere with each other.
Because of this problem, in U.S. Pat. No. 3,095,600 for example, the front rotary link has been considerably curved or, in U.S. Pat. No. 3,275,370, the front side door has been integrally formed with part of the front fender, whereby the interference of the rotary link with the front fender is avoidable.
However, in the case of the former, such disadvantages are presented that the mechanical strength of the curved rotary link decreased and a space for receiving the rotary link when the door is closed is excessively large.
In the case of the latter, such disadvantages are presented that of the weight and the area of the side door are increased, so that the side door with a design of some unusual shape, cannot be applied to normal passenger cars.